Note 9 - Income Taxes - Deferred Tax Assets and Liabilities (Details) - USD ($) |
Dec. 31, 2021 |
Dec. 31, 2020 |
|---|---|---|
| Net operating loss carryforward | $ 18,449,694 | $ 14,737,240 |
| Research and development tax credit carryforward | 1,566,293 | 1,189,110 |
| Stock-based compensation expense | 129,475 | 4,870 |
| Accrued salaries | 69,940 | 72,721 |
| Total deferred tax assets | 20,215,402 | 16,003,941 |
| Depreciation | 30,945 | 28,274 |
| Net deferred tax assets | 20,184,457 | 15,975,667 |
| Valuation allowance | (20,184,457) | (15,975,667) |
| Net deferred tax asset after reduction for valuation allowance | $ 0 | $ 0 |